I think ur code prints ( i havent run ur code) 1 * 2 + 1 = k 2 * 2 + 1 = k etc If it is so then the error is clear, u never computer the value (k) you wanted to display. replace ur lines with these for ( int i = 1; i <= 10; i++ ) { k= i*2+1; System.out.printf( "%d * 2 + 1 = %d\n", i,k); } try this out and let us know. You seem to be new to Java, if so do ur homework sathi.